Seal down shingle



April 1966 D. E. LovNEss v 3,247,631

SEAL DOWN SHINGLE Filed. Feb. 18, 1959 00mm) 5 lam 55 5/ Arrow 2 United States Patent 3,247,631 SEAL DOWN SHINGLE Donald E. Lovness, Stillwater, Minn., assignor to Minnesota Mining 8; Manufacturing Company, St. Paul, Minn., a corporation of Delaware Filed Feb. 18, 1959, Ser. No. 793,996 Claims. (Cl. 52173) This invention relates to strip shingles and roll roofing for surfacing roofing and siding. More specifically, this invention relates to a seal-down asphalt shingle construction, and to a contact adherent material possessing unique characteristics as a roofing adhesive.

conventionally, asphalt strip shingles are formed from asphalt impregnated felt or the like having the top surface, and sometimes the under surface thereof, coated with asphalt. Usually, the top surface is further surfaced with mineral granules, either colored or plain, to provide a finished appearance. These asphalt, granule coated strip shingles are subject to an almost endless variety of shapes, sizes and colors. However, these shingles all come under the general category in the art known as asphalt strip shingles.

These strip shingles, when applied as roofing or siding, are conventionally overlapped with one another so that each shingle has a hidden portion and an exposed portion overlying the hidden portion of the next adjacent lower shingle. Generally, the hidden portion of the shingle is called the headlap and the exposed portion the tab, the shingles being tacked or stapled or otherwise fastened to the roof or siding to be covered through the headlap portion so that the fastening means is not exposed to the weather but is covered by the shingle tabs.

While this arrangement is eminently satisfactory for most purposes, an ever-present problem is that of preventing high winds from sluicing under the shingle tabs, thereby lifting the shingles and tearing them from their fastening means,

One approach to the production of a seal-down shingle as a solution of this problem has been to apply a stripe or band of adhesive across the strip shingle adjacent the juncture of the headlap portion to the tab, with the thought that by adhering the top surface of an underlying shingle to the under surface of its overlying shingle generally along the line of juncture of the headlap and tab portions of such overlying shingle, the space beyond the tab would be sealed against wind penetration. Thus, ideally, the shingles are sealed down and wind cannot penetrate under the headlap portions of the shingles and lift them from their anchorage.

Two types of adhesives have been previously tried in this approach, one being a brittle asphaltic pitch adhesive and the other being a normally soft asphalt-rubber based adhesive. The brittle adhesives are unsatisfactory in many respects as they are quite frangible and tend to split-off and fracture upon handling and/ or impact whereupon even their potential adhesion value is lost. Even when maintained intact, they adhere only when heated for long continuous periods, as by direct exposure to the radiant heat of the sun to maintain the shingle adhesive at relatively high temperatures; i.e., over about 120 F., for 24 hours, and they tend to flow and bleed onto the shingle surface at about the same temperature at which adherence is obtained. Thus, quite often they provide no seal-down" function, and other times sacrifice roofing appearance for limited adhesion.

The soft adhesives heretofore proposed to avoid the aforementioned, and other, shortcomings of brittle adhesives have been beset with their own problems. These adhesives require relatively expensive crude rubber or reclaimed rubber formulations which have poor shelf life when coated and exposed to air and which lose tack 3,247,631 Patented Apr. 26, 1966 quickly upon exposure to ultra-violet light. These adhesives tend to flow at about the temperature they adhere and, like the brittle adhesives, have little temperature stability, being capable of adherence on contact through only minor temperature variations.

Because of the foregoing, and other problems incident to their use, seal-down asphalt strip shingles have had little success in the marketplace heretofore.

This invention provides seal-down asphaltic strip shingles which are free from the aforementioned difiiculties heretofore encountered in seal-down asphalt shingle constructions.

The seal-down shingles of this invention are formed of conventional asphaltic strip shingles surfaces with a soft contact adherent adhesive possessing a unique combination of desirable seal-down characteristics especially applicable to seal-down shingles.

This new contact adherent adhesive comprises an inert, high molecular weight, oxygenated paraffin resin tackified with and stabilized by the addition thereto of a lubricating oil viscosity stabilizer. In addition to its unique utility as a seal-down adhesive in an asphalt strip shingle, this adhesive displays desired qualities in other roofing areas. Thus, this adhesive can be used as a surface coating for asphalt roll roofing to seal it directly to roof sheathing; and, the adhesive has use as a flashing adhesive, and as an adhesive seal for roll roofing seams.

By oxygenated paraffin resin as used in this specification is meant a thermoplastic condensation product substantially free from asphaltenes and being chemically condensed in the presence of air from a natural viscous precipitate separated by a warm hydrocarbon precipitant from a residual parafiin base oil fraction derived from a crude oil containing no more than about 0.2% asphaltenes. These resins may be obtained in accordance with Patent No. 2,337,336 issued to McCluer and Hulferd on December 21, 1943.

The oxygenated thermoplastic paraflin resins useful in the formation of the shingle adhesive compositions of this invention are those high molecular weight, soft, flexible resins having a minimum softening point, ring and ball method, ASTM E28-42T, of about F. and a needle penetration value at 77 F. of between about 50 and 80, as measured by ASTM D5-25. The molecular weight of these soft, flexible resins is diflicult to determine; however, recent estimates place this weight in the neighborhood of from 70,000 to about 100,000 rather than the range noted in Patent No. 2,337,336 supra.

While these resins possess both adhesive and cohesive strength, they are preferably combined with a tackifying agent for contact adherence in the formulation of the shingle adhesives of this invention.

A particular oxygenated parafiin resin that has been found to provide an excellent adhesive is marketed by Kendall Refining Co. as a normally solid, flexible, high molecular weight oxygenated paraffin resin containing ester linkages and extracted from Pennsylvania parafiin base crude cylinder-oil stock. This resin is composed of a series of microgels, which can be observed under an electron microscope, and has a viscosity in the range of 800 centipoises at 386 F., a softening range of 180 210 F. using ring and ball method, AST M E28-4ZT, and a needle penetration value at 77 F. of about 47-76, as measured by ASTM method D5-25.

The members of this family of resins are characterized as oxygenated parafiin resins of relatively high molecular weights, e.g., on the order of magnitude of 100,000, and containing ester linkages. Other similar resins can be made containing various functional groups. The addition of sulfide groups to these oxygenated parafiin resins is, in fact, believed to enhance the already good ultra-violet resistance of the resins.

In the formulation of shingle adhesives a group of tackifying agents has been discovered which not only tackify the resin surface for contact adhesion without adversely affecting the softening range of the resin, but which tend to stabilize the viscosity of the resin in the temperature range normally encountered in the laying and normal weathering of roofing. These tackifying agents are commercially available as lubricating oil viscosity stabilizers.

In the formation of the adhesive, a small amount of a lubricating oil viscosity stabilizer is added to the oxygenated paraflin resin, after first heating the resin to about 350-425 F., and thoroughly mixed therewith. The resultant mass upon cooling is the soft, flexible, solid, tacky surfaced contact adherent adhesive of this invention. While considerable tolerance in the amount of viscosity stabilizer, as a percentage of the total weight of the mass, is possible depending on the staibilizer utilized, it has been found that either too little or too much stabilizer results in a material having inferior properties as a shingle adhesive.

Utilizing two commercially available lubricating oil viscosity stabilizers, namely a 37 /2% solids polyalkyl methacrylate polymer in lubricating oil and a 20% solids polyisobutylene polymer in lubricating oil, as modifiers for the preferred resin, the useful range of stabilizer to total adhesive weight has been found to be from about 5% to about 20% stabilizer. Since lubricating oil viscosity stabilizers are generally marketed as 2040% solids in oil, this stabilizer range of the preferred stabilizers is believed to be a good rule of thumb for all stabilizers. The preferred stabilizers, because of better resin compatibilitiy, are the polyisobutylene in oil solutions; the polyisobutylenes utilized for this purpose generally having molecular weights averaging from 10,000 to 15,000. The preferred range of polyisobutylene in oil stabilizer to total adhesive weight has been found to be around The resulting adhesives are solvent-free, soft, tacky surfaced solid contact adherent materials which adhere on contact therewith to asphat shingles throughout a temperature range of from about 40 F. to about 150 F. These adhesives possess needle penetration values of about 60110 at 77 F. following ASTM method D5-25, in the manner indicated hereinbefore, and a ring and ball softening range of 180-200 F., indicating little variation from the corresponding measurements of the parent resin.

In the utilization of the adhesive in the formation of an asphalt granule coated seal-down strip shingle, each strip shingle is provided with a stripe or band, either of a continuous or of an interrupted nature, of the adhesive across the top surface thereof for adhering the undersurface of an overlapping shingle thereto. To facilitate bundling, each shingle is provided with a groove across the undersurface thereof coextensive with the raised stripe or band. Preferably the groove is wider than and at least as deep as the adhesive stripe, and is lined with a permanent adhesive release coating.

Preferred release coatings for these oxygenated paraffin resin based adhesives have been found to be certain silicones which may be applied to the groove surface as coatings. While these silicones may be impregnated or coated on paper, or other backing strip, which backing strip may then be glued or otherwise adhered to the undersurface of the groove, such alternative is relatively expensive.

Commercially available silicones which can be moditied to provide adhesive release coatings of the nature desired are marketed as DC-22 and DC23 (and more recently as Syl-Oif 22 and Syl-Otf 23 respectively) by Dow Corning Co., the former being an aqueous emulsion of a 40% by weight solids of essentially dimethyl polysiloxane containing some hydrogen bonded silane groups, and the latter being a 30% by weight solids in xylene of the same polysiloxane. Both of these silicones appear to be cross linked through the silane bonded hydrogens to form silicone rubbers.

In the preparation of DC-23" as an adhesive release coating which may be brushed or sprayed on the groove surface, the following formulation has been found satisfactory:

Percent by weight DC-23 16.7 Organo-tin catalyst (DC23 catalyst) for cross linking .3

Methyl ethyl ketone 83.0

DC-22 10.0 2% carboxy methyl cellulose in water 87.5 Glacial acetic acid 0.5 Organo-tin catalyst for cross linking (XY-27, Dow

Corning) 2.0

Referring now to the accompanying drawings, there is illustrated therein a preferred embodiment of the invention wherein:

FIGURE 1 is a front view of a strip shingle constructed in accordance with this invention;

FIGURE 2 is an end view of the strip shingle of FIGURE 1;

FIGURE 3 is an end view of a modified shingle construction embodying the invention;

FIGURE 4 is a front elevational view of the strip shingles of FIGURE I laid up in lapping relation to cover a roof or siding surface; and

FIGURE 5 is an end elevational view of a bundle of shingles embodying the invention with part of the covering of the bundle being broken away to disclose the stacked relation of the shingles to one another.

With more particular reference to the accompanying drawings, it will be appreciated that the drawings are illustrative only, and not drawn to any particular scale. Thus, for example, the thicknesses shown on the end views of FIGURES 2, 3 and 5 are exaggerated for clarity of detail, as is the thickness of the adhesive stripe.

Referring first to FIGURE 1, there is illustrated therein a conventional type of granule coated asphalt strip shingle designated in its entirety by the numeral 10. While a particular strip shingle has been chosen for convenience of illustration, the use of differently patterned and formed shingles is also contemplated by this invention.

These asphalt strip shingles comprise generally a headlap portion 12 and a tab portion 14, the top surface of the shingle being customarily surfaced with roofing granules 16. Each strip has a plurality of shingle tabs 14. Extending across the top surface of the shingle is a stripe of a soft, contact adherent, tacky surfaced adhesive 18 of the nature of the oxygenated paraffin resinpolyisobutylene adhesive described hereinbefore. While the adhesive stripe or band 18 is shown as an interrupted stripe, it may be continuous if desired. The stripe may be applied by first softening the adhesive at a temperature of about 350 F. and calendering the stripe on the granuled surface while the adhesive is hot.

This adhesive stripe extends in a -line across the headlap portion of the shingle slightly above the tabs thereof in order that the stripe will serve to seal down the tabs of overlapping shingles when the shingles are laid up to cover a roofing or siding as illustrated by the ship-lap lay-up of FIGURE 4.

Referring to FIGURE 2, it will be seen that the adhesive stripe 18 is raised above the top surface of the shingle. To accommodate this stripe when the shingles are bundled as disclosed in FIGURE 5, the undersurface of the'shingle has a groove or slot 20, which like the adhesive stripe, may be continuous or discontinuous, extending the length thereof coextensive with the stripe 18. The stripe is preferably slightly wider than and at least as deep as the stripe 18 for ease of bundling.

The surface of the groove is preferably lined with an adhesive release coating, as indicated in FIGURE 2, so that when the shingles are bundled, the adhesive stripe of the next lower shingle on the stack or bundle, as shown in FIGURE 5, nests within the groove 20 of the overlying shingle in a manner that does not increase the bulk of the bundle or entail special bundling techniques. The release coating lining the groove 20 prevents any sticking of the adhesive stripe 18 of the next lower shingle thereto during bundling or upon removal of the shingles from the bundle.

This construction eliminates any necessity for a separate covering strip over the adhesive stripe 18 which must be peeled therefrom when it is desired to lay the shingles. Further, since the adhesive release medium when applied as a coating, is easily and inexpensively applied and forms a permanent part of the shingle structure itself, there is no necessity for a separate adhesive release strip.

In FIGURE 3 there is a somewhat modified shingle structure shown in end view, the modification residing in the utilization of a separate release strip 22 glued to the under surface of the groove 20 as the release medium, rather than a release coating as illustrated in FIGURE 2.

With either of the constructions of FIGURES 2 and 3, the shingles may be bundled in the conventional manner shown in FIGURE 5 wherein a portion of the bundle wrapping 26 is shown as being torn away to display the nesting of the adhesive stripes 18 in the shingle grooves 20. A removable adhesive release strip 24 is shown covering the stripe of the top shingle of the bundle, the only one requiring such a strip.

In laying up these shingles in the covering of a roof or the like as shown in FIGURE 4, the roof siding being designated by the numeral 28, the shingles are laid in lapped rows from the bottom to the top with the tabs 14 of the next higher row of shingles covering the headlap portions 12 of the next lower row of shingles and with the adhesive stripes 18 of the underlying shingles in registry with the tabs 14 of the overlying shingles. As they are laid up the shingles are fastened to the roof siding as is conventional by means of fasteners 26 or the like. The adhesive stripe 18 of the next lower row of shingles adheres to and seals down the tabs 14 of the next higher row of shingles upon pressing down of the tabs against this stripe. When thus sealed down, the shingle tabs are resistant to lifting by strong winds, being held in place by the adhesive stripe 18 of the next lower row of shingles.

The desirability of this shingle construction is greatly enhanced by the utilization of the particular adhesive hereinbefore described in the formation of the adhesive stripe or band 18 since this adhesive assures the contact adherence of the stripe to the overlying shingles throughout a temperature range as low as 40 F. and as high as 150 F. These adhesive characteristics in the formation of seal-down shingles are unique to this invention.

These adhesives have other uses in the field of asphalt roofing as indicated earlier, being useful as roll roofing hold down coatings for fiat and low pitch roofs, as well as forming ideal seam sealant-s between roll roofing strips. While readily brushed, coated, and calendered at temperatures above 350 F., these adhesives display no bleeding or other undesired flow characteristics at temperatures as high as 180 F., which is about as high a temperature as roofs are normally subjected to.

Since numerous modifications and changes may occur to those skilled in the art which fall within the purview 6 of the invention after a perusal of the foregoing description and the accompanying drawing, it is'to be understood the invention is not to be limited to the exact construction shown and described.

What is claimed is as follows:

1. A granule coated asphalt strip shingle having an adhesive stripe across the granule coated surface thereof, said adhesive stripe comprising a soft solid oxygenated paraffin resin substantially free from asphaltenes and having a minimum ring and ball softening point of about 175 F., and a needle penetration at 77 F. of about 50-80, tackified with from 540% by weight of a lubricating oil containing 2040% by weight solids polyisobutylene.

2. A tacky surfaced, contact adherent adhesive composition comprising about 80-95% by weight of a high molecular weight, soft, normally solid oxygenated parafiin resin containing ester linkages and having a minimum ring and ball softening point of about 175 F. and a minimum needle penetration value of about 50-80 at 77 F., and about 520% by weight of a lubricating oil containing 20% solids polyisobutylene, said adhesive having a needle penetration value of about 60-110 at 77 F. and a ring and ball softening range of about 180200 F.

3. A seal-down asphalt strip shingle adapted to provide a lapped shingle covering resistant to lifting of the individual shingles by strong winds, said shingle having a raised stripe of a soft, tacky surfaced contact adherent adhesive along the top surface thereof for adherence with an underlying asphalt strip shingle, said adhesive comprising (1) a high molecular weight soft, flexible oxygenated parafiin resin having a minimum softening point, ring and ball method, of about 175 F. and a needle penetration value at 77 F. of between about 50 and 80, and (2) a lubricating oil containing from 20-40% of a lubricating oil viscosity stabilizer, there being from 5 to 20 parts (2) for each parts (1), said adhesive being contact adherent to asphalt throughout a temperature range of from 40 F. to about F.

4. The seal-down shingle of claim 3 wherein said shingle has a groove along the undersurface thereof being slightly deeper and wider than said stripe for nestingly receiving the raised stripe of an underlying shingle when a plurality of such shingles are stacked for bundling, and a silicone adhesive release coating lining said groove.

5. A seal-down asphalt strip shingle having a granule coated top surface and comprising a headlap portion with shingle tabs depending therefrom, said headlap portion having a raised stripe of a soft, tacky surfaced contact adherent adhesive comprising 80-95% by weight of an oxygenated paraffin resin, and about 520% by weight of a lubricating oil compatible therewith containing 20- 40% lubricating oil viscosity stabilizing polymer of polyisobutylene as solid content thereof, said shingle having a groove along the under surface of the headlap port-ion thereof coextensive with said raised stripe and being wider than said stripe for nestingly receiving the raised stripe of an underlying shingle when a plurality of such strip shingles are stacked for bundling, and an adhesive release medium for said adhesive lining said groove.

References Cited by the Examiner UNITED STATES PATENTS 2,142,030 12/1938 Abrams et al. 26028.5 2,210,209 8/1940 Kirschbraum 52-420 2,337,336 12/1943 McCluer et al. 2083 2,387,593 10/1945 Lesser 117-122 X 2,565,509 8/1951 Marcin.

(Uther references on following page) UNITED STATES PATENTS Foehr 208-3 Lei brook 52-42O Dunbar 52-420 Liebrook et a1. 52420 Liebrook 52-420 Fasold et a1. 52543 8 OTHER REFERENCES Petroleum Refining With Chemicals by Kalichevsky, 1956, pages 549 and 550.

5 FRANK L. ABBOTT, Primary Examiner.

JACOB L. NACKENOFF, WILLIAM I. MUSHAKE, Examiners. 

1. A GRANULE COATED ASPHALT STRIP SHINGLE HAVING AN ADHESIVE STRIP ACROSS THE GRANULE COATED SURFACE THEREOF, SAID ADHSEIVE STRIPE COMPRISING A SOFT SOLID OXYGENATED PARAFFIN RESIN SUBSTANTIALLY FREE FROM ASPHALTENES AND HAVING A MINIMUM RING AND BALL SOFTENING POINT OF ABOUT 175* F., AND A NEEDLE PENETRATION AT 77* F. OF ABOUT 50-80, TACKIFIED WITH FROM 5-20% BY WEIGHT OF A LUBRICATING OIL CONTAINING 20-40% BY WEIGHT SOLIDS POLYISOBUTYLENE. 